/Engine/Source/Runtime/InteractiveToolsFramework/Public/BaseGizmos/GizmoMath.h
Project the input Point into the plane defined by PlaneOrigin and PlaneNormal, and then calculate it's UV coordinates in the space defined by the plane axes PlaneAxis1 and PlaneAxis2
the UV coordinates
namespace GizmoMath { FVector2D GizmoMath::ComputeCoordinatesInPlane ( const FVector & Point, const FVector & PlaneOrigin, const FVector & PlaneNormal, const FVector & PlaneAxis1, const FVector & PlaneAxis2 ) }